The invention relates to a hub cap with picture for a rim of a wheel of a vehicle, comprising a housing connected to the rim, a disc connected rotatably to the housing, on the side of which disc remote from the housing the picture is arranged, wherein the rotatable connection between housing and disc is formed by a pivot pin which is received rotatably in a pivot hole, and a mass which is connected to the disc at a distance from the pivot pin.
Such a hub cap is used during rotation of the rim to hold the disc with picture in a stable position of equilibrium, such that the picture is visible when the vehicle moves and will always be displayed upright when the vehicle is stationary.
Tests have shown that this hub cap does not function adequately. The picture is still co-rotated somewhat during rotation of the rim.
The invention has for its object to provide an improved hub cap. For this purpose the hub cap has the feature that the mass is connected to the disc for pivoting on a first shaft parallel to the pivot pin. Because the mass has a smaller moment of inertia than the disc, the disc will undergo a smaller angular displacement than the mass during acceleration or deceleration of the vehicle. The relatively larger angular displacement of the mass will result in this case in a better, or in any case quicker, stabilization of the disc.
The first shaft is preferably located close to the pivot pin so as to enhance the above-described effect as much as possible.
In addition, the mass is preferably arranged for displacement in radial direction relative to the first shaft. Hereby is prevented that the stabilization effect is negatively affected by movements of the wheel in a direction perpendicular to the direction of travel of the vehicle. If a vehicle drives for instance through a pot-hole, the mass can absorb this jolt by displacing in radial direction.
In this case it is advantageous if damping means are provided for slowing the movement of the mass in the radial direction.
In a preferred embodiment the mass is arranged relative to the first shaft for pivoting on a second shaft located at a distance from the first shaft and the pivot pin. It has been found from tests that this further enhances the stabilizing effect of the mass on the disc.
The disc is provided with a hub for receiving the pivot pin arranged on the housing. In this embodiment the hub is stationary. This prevents the mass coming into contact with rotating elements of the hub cap, whereby the mass would receive an extra impulse during deceleration or acceleration of the vehicle, this having a negative effect on the stabilizing action thereof.